Hammers



Oct. 11, 1966 T. A. RATKOWSKI 3,278,126

HAMMERS Filed Sept. 1?, 1963 2 Sheets-Sheet 1 Inventor Thomas ARa'tkou/ski Bg/ and DM fi-l-torne 1&6

Oct. 11, 1966 T. A. RATKOWSKI 3,278,126

HAMMERS Filed Sept. 17, 1963 2 Sheets-Sheet 2 111v e n to P Thomas A. Ratkows k-i Bg/ lifeline, dad/Dam .fl-l-korrzegs United States Patent 3,273,126 HAMMERS Thomas A. Ratlrowski, Chicago Heights, Ill., assignor to Ahex Corporation, a corporation of Delaware Filed Sept. 17, 1963, Ser. No. 309,518 4 Claims. (Cl. 241195) This invention relates to hammers for installation in a hammer mill, and more particularly to hammers of a large size and weight.

Hammers employed in a hammer mill are often made of cast austenitic manganese steel alloy because of the extreme resistance of this alloy to shock and its tendency to harden progressively with impact. To obtain an austenitic structure in manganese steel, it is necessary to heat treat the manganese steel after casting. While heretofore it has been desired to have large size and weight of hammers of austenitic manganese steel, as for example in excess of three hundred pounds, metal castings of such size are diflicult to produce and heat treat as the metal sections of the casting must of necessity be of extremely large thickness, making it difiicult to produce as a casting and to heat treat these metal sections.

Accordingly, an object of the present invention is to achieve a large size cast hammer by resorting to a unique geometry for the hammer. A more specific object of the invention is to obtain a large cast hammer wherein supporting arms are of austenitic steel and possess sufiicient size and strength to undergo the forces encountered in a hammering operation.

In hammer mills it is important that the hammers be balanced and of a proper weight compared to the weight of the other hammers employed in the same hammer mill so that the hammer mill will be properly in dynamic balance when the hammers are rotating. Since large castings vary in their cast weights by a few pounds and seldom are specified, grinding operations on the hammer castings have in the past been employed to reduce the weight of the castings to a given standard. A further object of the invention is to balance a casting by adding additional weight to the interior of the casting and thereby provide additional weight to the interior of the casting and thereby provide additional hammering force to a hammer.

More particularly, an object of the invention is to balance a hammer of large size and to increase its weight by lead shot, which additionally affords a better hammering action by reducing the amount of rebound of the head of the hammer striking against the material to be comminuted in the hammer mill.

Under a further object of the invention, a hammer is formed of austenitic manganese steel with the head and the supporting arms being hollowed to permit a uniform heat treating of a cross sectional area of the head and arms and with the weight of the hollowed out portions being replaced by an interior ballast of lead shot.

Other and further object of the present invention will be apparent from the following description and claims and are illustrated in the accompanying drawings which, by way of illustration, show a preferred embodiment of the present invention and the principles thereof and what is now considered to be the best mode contemplated for applying these principles. Other embodiments of the invention embodying the same or equivalent principles may be used and structural changes may be made as desired by those skilled in the art without departing from the present invention and the purview of the appended claims.

In the drawings:

FIG. 1 is a sectional view showing a plurality of hammers mounted on a support rod in a hammer mill.

FIG. 2 is a large perspective showing cavities formed in the hammer castings.

FIG. 3 is a sectional View of a conventional hammer mill with the replaceable hammers mounted thereon.

FIG. 4 is an end view of the hammer.

FIG. 5 is a sectional view showing the cavities in the hammer.

FIG. 6 is a sectional view along the line 66 of FIG. 5 and showing a sealing plug for the internal cavities.

Referring now to FIGS. 1 and 3 in the drawings, there is illustrated a conventional hammer mill 10 having a plurality of circular disks 12 for supporting a plurality of hammers 14 on a supporting shaft 17. The hammer mill 10 is merely illustrative of one environment for the hammer 14 of the present invention, and hence it will be appreciated that the hammer 14 may be used in a mill of substantially different geometry and capacity.

As will be apparent from FIGS. 1 and 3, three hammers 14 will be supported on each of the shafts 17. Each of the hammers 14 has a pair of spaced supporting arms or shanks inserted between the peripheries of a pair of adjacent supporting disks 12. Since the supporting disks 12 carry three shafts 17 and since there are three hammers on each shaft 17, a total of nine hammers are employed in the hammering mill 10. As seen in FIG. 3, the discs 12 are secured to a center drive shaft 22 which rotates the discs 12 and shafts 17, and thereby the attached hammers 14.

As the hammers 14 are carried around with the disks 12 in the course of the rotation of the drive shaft 22, the hammers 14 are effective as flails within the hammer mill 1%) to crush and disintegrate large size rocks or the like fed into the mill 10 through the opening 25 FIG. 3. The rocks or other coarse material will be broken up or granulated by the hammers 14 rotating into the crushing area of the mill defined by the space between the whirling hammers and a series of stepped impact blocks 26 which are related to the hammers within the mill. After the material is crushed to a finer size, it is discharged through an opening 28 at the bottom of the mill.

Each hammer 14 of the present invention is characterized by a relatively large head 30, and by the pair of integrally connected shanks or arms 20 having bores 29 for receiving a supporting shaft 17. The head St} has a flat surface 31, FIG. 5, at its free end terminating at beveled edges 32, FIG. 2, at the outer edges of the fiat surface 31. Extending upwardly from flat surface 31 are a pair of opposed end walls 33 and 34, each of which has semi-circular opening 35 therein. The heads 30 of the hammers 14 have opposed side walls 4t and 41, FIG. 4, which slope downwardly to intersect the flat surface 31 at the beveled edges 32.

As should be apparent from a consideration of FIGS. 2 and 5, the arms 2%) are formed with interal recesses or cavities 45. The cavities 45 are rectangular in crosssection and are joined to a rectangularly-shaped cavity 51) formed in the head 3t) and extending longitudinally between the opposed openings in the end walls 33 ant 34 of the head 30. Each recess communicates with an opening 48, FIG. 2. As seen in FIG. 5, the cavities 45 and are joined together, and in actual practice a single core piece having a pair of upstanding legs is employed during the casting of a hammer 14 to form upstanding legs and body. After the hammer 14 has been cast, the core is destroyed and removed through the openings 35 and 48 leaving the hollow cavities 45 and 50.

It will be appreciated that the cavities 45 and 50 are of substantial dimensions and thereby substantially re duce the weight of the hammer 14. To compensate for this weight, the hollow cavities 45 and 50 are filled with a comminuted lead shot 60, FIG. 6, through openings 35 and 48. To seal the shot 60 in the cavities, the openings or ports 35 and 48 are filled with a plug as 61, which is welded at 62, FIG. 6, to the head 30 at the opening 35. The lead shot 60 not only provides an efficient manner of increasing the weight of a hammer 14, but also provides an effective manner of readily balancing the weight of the hammer to exactly the same weight as the other hammers without requiring grinding or machining operations. More specifically, in large castings the weight of the casting often varies from a couple to as much as ten pounds in weight. To dynamically balance the weights of the hammers under one of the prior art practices, metal was ground or removed in a conventional manner from the hammer 14. Under the present invention, lead shot 60 is added to increase the weight of the hammer 14 to the desired weight. The lead shot 60 provides an additional advantage in that a better hammering action is obtained than from solid, one-piece hammers or hammers employing solidlly secured ballast or weights thereon, in that the lead shot 60 does not rebound directly with the casting as the casting hits a surface, but tends to dampen the rebound. That is, since the lead shot 60 is not integrally secured to the casting and is composed of comminuted particles capable of being compacted, the rebound of the hammer 14 in the opposite direction is resisted by the lead shot 60 being compacted as the hammer casting rebounds.

From the foregoing, it is believed to be apparent that larger hammers 14 can be obtained under the present invention by providing hollow cavities 45 in the supporting arms or shanks 20 to obtain a uniform austenitic structure of manganese steel throughout the arms or shanks 20. 7 Additionally, it is apparent from the foregoing that the loss of weight due to the cavities 45 and 50 can be readily compensated for by a ballast material, and that by using a ballast material such as lead shot that the Weight of the hammer can be easily brought up to the desired weight for dynamically balancing the hammers 14 in the hammer mill 10.

Additionally, the lead shot 60 apparently provides a better hammering operation in that it reduces the amount of rebound of a hammer 14 as it strikes the material being hammered.

Hence, while I have illustrated and described preferred embodiments of the present invention, it is to be understood that these are capable of variations and modification, and I therefore do not wish to be limited to the precise details set forth, but desire to avail myself of such changes and alterations as fall within the purview of the following claims.

I claim:

1. A hammer for installation in a hammer mill or the like where coarse material is to be comminuted to a fine size, comprising an elongated head; a pair of attaching arms projecting in spaced relationship from one side of said elongated head and adapted to be attached to a hammer supporting means within said mill, the arms and head of said hammer being formed with internal recesses therein for receiving ballast to increase the weight of the hammer; port means in said hammer and connected to said internal recesses; comminuted ballast being adapted to move through said port means to said internal recesses for increasing the weight of the hammer, and plug means for closing said port means to prevent the ballast from leaving said internal recesses through said port means during operation of the hammer.

2. A hammer for installation in a hammer mill or the like where coarse material is to be reduced to a finer size, comprising an elongated head presenting an end face at each end thereof; a pair of attaching arms projecting in spaced relationship from one side of said el-ongated head, and adapted to be attached to a hammer supporting means within said mill; the head of said hammer being formed with an elongated recess therein extending substantially parallel to the longitudinal axis of said head and terminating in openings at the end faces of the hammer head, enabling the filling of said elongated recess with a ballast material and the closing of the openings to retain the ballast material within said elongated recess.

3. A hammer for installation in a hammer mill or the like where coarse material is to be reduced to a finer size, comprising an elongated head presenting an end face at each end thereof; a pair of attaching arms projecting in spaced relationship from one side of said elongated head, and adapted to be attached to a hammer supporting means within said mill; the head of said hammer being formed with an elongated recess therein extending substantially parallel to the longitudinal axis of said head and terminating in openings at the end faces of the hammer head, enabling the filling of said elongated recess with a ballast material and the closing of the openings to retain the ballast material within said elongated recess; said elongated recesses being connected to recess extending within the interior of said attaching arms whereby said attaching arms also can be filled with said ballast material.

4. A hammer made of manganese steel having been heat-treated to have an austenitic structure throughout comprising an elongated head having an end face at each end thereof; a pair of attaching arms projecting in spaced relationship from one side of the hammer head and adapted to be attached to a hammer supporting means within a hammer mill; the head of said hammer being formed with an elongated recess extending substantially parallel to the longitudinal axis of said head and terminating in end openings at said end faces of said hammer head; each of said arms having an internal recess therein, said recesses in said arms and head being interconnected and filled with a ballast material; and plug means for plugging said end faces to retain said ballast within said hammer.

References (Iited by the Examiner UNITED STATES PATENTS 1,691,951 11/1928 Alfred 241 X 1,889,129, ll/1932 Nielsen 241195 2,015,581 9/1932 Armour 241--195 ROBERT C. RIORDON, Primary Examiner.

D. KELLY, Assistant Examiner. 

1. A HAMMER FOR INSTALLATION IN A HAMMER MILL OR THE LIKE WHERE COARSE MATERIAL IS TO BE COMMINUTED TO A FINE SIZE, COMPRISING AN ELONGATED HEAD; A PAIR OF ATTACHNG ARMS PROJECTING IN SPACED RELATIONSHIP FROM ONE SIDE OF SAID ELONGATED HEAD AND ADAPTED TO BE ATTACHED TO A HAMMER SUPPORTING MEANS WITHIN SAID MILL, THE ARMS AND HEAD OF SAID HAMMER BEING FORMED WITH INTERNAL RECESSES THEREIN FOR RECEIVING BALLAST TO INCREASE THE WEIGHT OF THE HAMMER; PORT MEANS IN SAID HAMMER AND CONNECTED TO SAID INTERNAL RECESSES; COMMINUTED BALLAST BEING ADAPTED TO MOVE THROUGH SAID PORT MEANS TO SAID INTERNAL RECESSES FOR INCREASING THE WEIGHT OF THE HAMMER, AND PLUG MEANS FOR CLOSING SAID PORT MEANS TO PREVENT THE BALLAST FROM LEAVING SAID INTERNAL RECESSES THROUGH SAID PORT MEANS DURING OPERATION OF THE HAMMER. 